What is the difference between 220 volts, 3 phase and 380 There is no need for a neutral wire to come to the kiln in this case, just an earth ground wire in addition to the 3 hot wires. 380/220 volts, 3 phase. If you have 380/220 volts and 3 phase power (like a lot of foreign countries), the kiln will come with a 4-wire powerblock for the 3 hot wires that give 3 phase and one neutral wire. Between 3-phase 4-wire Metering up to 480V : EKM Support Desk 3-phase 4-wire systems have 3 hot wires and a neutral wire. This could be a 480/277 volt system, or a 120/208 volt system. In the case of a 480/277 volt system, if you measure from any hot wire any other hot wire you will measure 480 volts and if you measure from any hot wire to neutral you will get 277 volts.
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